<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      /* .parent{
            display: flex;
            flex-direction: row;
        }
        .child{
            width:200px;
            height: 200px;
            background-color: blue;
        }
        .child2{
            flex: 1;
            background-color: red;
        } */

      .parent {
        overflow: hidden;
      }
      .child {
        float: left;
        width: 200px;
        height: 200px;
        background-color: blue;
      }
      .child2 {
        height: 200px;
        margin-left: 200px;
        background-color: red;
      }
    </style>
  </head>
  <body>
    <div class="parent">
      <div class="child">left</div>
      <div class="child2">right</div>
    </div>
  </body>
</html>
